In general, air conditioners are devices that control indoor air using a cooling cycle. Air conditioners cool an indoor space by intaking hot indoor air, performing heat exchange between the hot indoor air and a low-temperature refrigerant and then discharging the heat-exchanged air to the indoor space, or heats an indoor space by intaking low-temperature indoor air, performing heat exchange between the low-temperature indoor air and a high-temperature refrigerant, and then discharging the heat-exchanged air to the indoor space.
Air conditioners can cool or heat air of the indoor space through a cooling cycle in which the air is circulated through a compressor, an outdoor heat exchanger (condenser), an expansion valve, and an indoor heat exchanger (evaporator) in a forward or backward direction. The compressor provides a gaseous refrigerant in a high-temperature high-pressure state, and the condenser provides a refrigerant in a liquid state in a room-temperature high-pressure state. The expansion valve decompresses the liquid refrigerant in a room-temperature high-pressure state, and the evaporator evaporates the decompressed gaseous refrigerant in a low-temperature state.
In a separation type air conditioner in which an outdoor unit and an indoor unit of the air conditioner are installed to be separated from each other, the compressor and the outdoor heat exchanger are provided for the outdoor unit.
The outdoor unit is disposed outside a building and is exposed to an external environment. In winter, when there is a large amount of snow cover, the outdoor unit can freeze due to snow or rain and does not operate.